Deterioration refers to the common perception of cognitive aging where individuals are viewed as passive victims of the decline in competent thought and behavior.
Longitudinal research regarding intelligence changes with age suggests a slight rise in IQ through middle adulthood. While total IQ scores may start to decline around 67-74 years, the decline is not substantial. Overall, intelligence measured by IQ remains highly stable over a person's lifetime.
Crystallized intelligence consists of skills and knowledge acquired through experience and education.Onstandardized tests, crystallized abilities are measured by vocaband by verbal comprehension.Crystallized abilities are heavily dependent on education.
Fluid intelligence involves basic abilities under the influence of biological processes, such as adapting to new situations. A common measure is a sequence-completion puzzle, hence fluid abilities require abstract reasoning.
Semantic memory increases from 35-55 years, leveling off afterward. While semantic memory starts to decline at 65, the decline is less substantial compared to episodic memory.
With age, there is disproportionate volume loss in the hippocampus, prefrontal cortex, and amygdala. Reduced communication between neurons leads to slower cognitive processing. Aging is associated with reduced blood flow, increased free radical damage, and inflammation in the brain.
Episodic memory consolidation helps explain why older individuals may remember events from their youth better than recent events, as memory consolidation becomes less efficient with age.
Older adults are more likely to remember events that are emotionally significant to them as emotionally salient events are processed more deeply and stored in long-term memory, contributing to better recall.
The brain adapts to age-related changes through plasticity and neural compensation, allowing it to recruit different structures or systems to compensate for age-related declines. Older adults may activate frontal areas more broadly to compensate for declines inventral striatum.
Older adults are more likely to use “Win-stay/lose-shift" strategy, making better decisions in real-world contexts where rewards and punishments are often unpredictable.
Neurological case of Patient HM is that he lived 55 years without the hippocampus and so he could not formnew memories due to problem with episodic memory, demonstrating that hippocampal damageimpairsmemory.